Controlled electrical pulse source

ABSTRACT

A triggered blocking oscillator includes a charging transistor connected in series with the primary of an oscillator transformer which includes a secondary connected in series with a diode to charge a capacitor. The capacitor is also connected to the engine distributor in series with a silicon controlled rectifier. The transformer includes a control winding connected to fire the rectifier. A control transistor is connected in the base circuit of the main charging control transistor with the input of the control transistor connected in circuit through a silicon controlled rectifier. The gate of the silicon controlled rectifier and the base of the control transistor are connected to a battery in series with breaker points of the internalcombustion engine to provide periodic turn-on pulses to the silicon controlled rectifier and transistor. A square loop core unit is connected to divert current from the silicon controlled rectifier and the input of the control transistor. When the circuit is first turned on, the current increases until such time as the square loop core unit is saturated. At that time, the reactance of the square loop core unit decreases diverting the current around the silicon controlled rectifier and control transistor and effectively turning them off. This, in turn, turns off the main transistor and provides the pulse transfer.

United tates Patent Minlss Aug. 29, 1972 [54] CONTROLLED ELECTRICALPULSE SOURCE [72] Inventor: Eloydlt'l: RT. #1, Port Washington, ll/K531?[22] Filed: Oct. 4,1965

21 Appl. No.: 492,570

[52] US. Cl. ..123/148 E, 315/209 [51] Int. Cl ..F02d 11/10 [58] Fieldof Search ..123/148 E; 315/209 CD; 33l/1l2,146,148, 149

[5 6] References Cited UNITED STATES PATENTS 3,297,911 l/1967 Quinn..315/214 3,302,629 2/1967 Shano ..123/148 E 3,312,211 4/1967 Boyer..123/148 E Primary Examiner--Laurence M. Goodridge AttorneyAndrus,Sceales, Starke & Sawall [57] ABSTRACT A triggered blocking oscillatorincludes a charging transistor connected in series with the primary ofan oscillator transformer which includes a secondary connected in serieswith a diode to charge a capacitor. The capacitor is also connected tothe engine distributor in series with a silicon controlled rectifier.The transformer includes a control winding connected to fire therectifier. A control transistor is connected in the base circuit of themain charging control transistor with the input of the controltransistor connected in circuit through a silicon controlled rectifier.The gate of the silicon controlled rectifier and the base of the controltransistor are connected to a battery in series with breaker points ofthe internal-combustion engine to provide periodic turn-on pulses to thesilicon controlled rectifier and transistor. A square loop core unit isconnected to divert current from the silicon controlled rectifier andthe input of the control transistor. When the circuit is first turnedon, the current increases until such time as the square loop core unitis saturated. At that time, the reactance of the square loop core unitdecreases diverting the current around the silicon controlled rectifierand control transistor and effectively turning them off. This, in turn,turns off the main transistor and provides the pulse transfer.

7 Claims, 1 Drawing Figure do as PATENTEnAucze m2 INVENTOR. FLOYD M.MINKS BY 74n drus Siarl@ AfFonwsYs CONTROLLED ELECTRICAL PULSE SOURCEThis invention relates to a controlled electrical pulse source andparticularly to a pulse source for capacitor discharge ignition systemsfor internal-combustion engines and the like.

Electronic ignition systems for internal-combustion engines have beensuggested for a number of years wherein a capacitor is charged from thebattery and/or the generator and is rapidly discharged through theinduction coil of the usual ignition unit to fire a spark plug. Therecent development of solid state devices such as transistors, siliconcontrolled rectifiers and the like provided a highly satisfactoryamplifying and switching means for controlled charging and switching ofthe capacitor circuit. A highly satisfactory capacitor dischargeignition system is shown in applicants copending application entitledCapacitor Ignition System which was filed on Mar. 1, 1965 with Ser. No.436,118, now US. Pat. No. 3,369,151.

The present invention is directed to an improved pulse sourceparticularly applicable to capacitor discharge systems wherein theamount of energy for each pulse is regulated through a control meansconnected in the charging circuit for the capacitor. Generally, inaccordance with the present invention, a triggered blocking oscillatorof an improved and novel construction is provided having a controlcircuit connected in the feedback circuit to determine the time thateach pulse begins and the energy per pulse. In a preferred construction,a transistor is connected in series with the primary of an oscillatortransformer means. Timed switching means are provided for periodicallyinitiating conduction through the transistor to provide a pulse from thebattery or other direct current (D.C.) source to the transformerprimary. The switching means is connected in a feedback loop controlhaving a magnetic core unit connected in the circuit to permitconduction of said switch means until the core of the unit is saturatedat which time the rapid change in the permeability of the coreunit'causes a diversion of current and turn-off of the transistor. Thecore unit may advantageously employ a square loop type core material;that is, one with essentially a rectangular magnetic characteristic. Thetransistor rapidly turns off causing a decay in the flux in thetransformer. At this time, the transformer provides an output pulsecharging the capacitor which is subsequently discharged to the ignitionspark plug or other ignition unit of the internal-combustion engine.

In a preferred construction of the present invention, the triggering andthe feedback circuit employs a control transistor connected in the basecircuit of the main charging control transistor with the input of thecontrol transistor connected in circuit through a silicon controlledrectifier or the like. The gate of the silicon controlled rectifier andthe base of the control transistor are connected to a suitable signalsource which in turn is controlled in accordance with the timing of theinternal-combustion engine to provide periodic turn-on pulses to thesilicon controlled rectifier and transistor. The square loop core unitis connected to divert current from the silicon controlled rectifier andthe input of the control transistor. Consequently, when the circuit isfirst turned on, the current increases until such time as the squareloop core unit is saturated. At that time, the reactance of the squareloop core unit decreases diverting the current around the siliconcontrolled rectifier and control transistor and effectively turning themoff. This, in turn, turns off the main transistor and provides the pulsetransfer as noted above. Thus, the conduction is initiated by the tum-onpulse and terminated by the magnetic energy regulator. The unittherefore acts as a gated or triggered oscillator and not as anamplifier of the input pulse.

The present invention thus provides a highly efficient means forregulating the energy per pulse for capacitor discharge ignition systemsand thelike. The circuit of the present invention provides a desiredoutput over a wide variation in the input and essentially eliminatesvariation in engine performance with changes in battery or sourcevoltage. This will prevent generation of abnormally damaging voltages orcurrents in the operating circuit or the ignition system with variationin the input voltage or the gain of the semi-conductors and willmaintain the same performance with these as well as variation in speed.The output energy is also independent of the value of the capacitor 5over a broad range of capacity values.

The drawing furnished herewith illustrates a preferred construction ofthe present invention in which the above advantages and features areclearly disclosed as well as others which will be clear from thefollowing description of the drawing.

The drawing is a schematic circuit diagram of an ignition systemconstructed in accordance with the present invention.

Referring to the drawing, the illustrated ignition system is connectedto a direct current source such as a low voltage battery 1 having asuitable rated output voltage such as 6, 12 or 24 volts all of which arepresently employed in automobiles, trucks, outboard motors or othersimilar internal-combustion engines. A single spark gap 2 is illustratedforming a part of a combustion chamber of the prime mover. Inmulticylinder engines, a plurality of spark gaps will normally beemployed with a distributor 3, shown in block diagram, provided tosequentially distribute the power to the several gaps in accordance withknown practice. The illustrated embodiment of the present inventionemploys a pulse transformer 4 which couples the spark gap 2 to acapacitor discharge circuit including a storage capacitor 5 connected tobe discharged through the transformer 4 in series with a siliconcontrolled rectifier 6. A firing control transformer winding 7 isconnected to the rectifier 6 and provides controlled firing thereof intimed relation to the operation of the internal-combustion engine andthe distributor 3 as hereinafter described and thereby causes propertransfer of energy from the capacitor 5 to gap 2.

The capacitor 5 is connected to be charged from the battery 1 through atriggered blocking oscillator 8 which includes a square loop core unit 9to regulate the energy per pulse as hereinafter described.

An input switch 10 is coupled to be actuated in synchronism with theoperation of the engine, diagrammatically shown coupled to the operationof the distributor 3, to provide periodic triggering of the blockingoscillator 8 into conduction.

The oscillator 8 generally includes a charging transistor 11 connectedin series with a primary 12 of a transfer or oscillating transformer 13.A secondary l4 of transformer 13 is connected in a charging circuit withthe capacitor 5, as hereinafter described. The circuit is such thatduring the conduction through the primary 12 from the battery 1 thecapacitor circuit is effectively opened. When the current through thetransformer primary 12 is cut ofi, a pulse is generated in the secondarywhich is conducted to charge the capacitor 5. This charge is transmittedto the gap 2 as noted above at the initiation of the subsequent chargingof the transformer 13.

Generally, the circuit operation includes the opening of the switch 11to initiate operation of the oscillator 8 which derives power from thebattery 1 with a portion of the current passing through the square loopcore unit 9. When the square loop core unit is saturated however it willrapidly turn off the oscillator 8 and the collapsing field intransformer 13 produces a current in the secondary M which chargescapacitor 5 to a corresponding level. The square loop core unit 9determines the on time of the oscillator 8 as a function of the batteryvoltage and therefore regulates the energy in the pulse transferred tothe capacitor 5. The silicon controlled rectifier 6 is fired thereforeby a pulse generated in winding 7, which is wound as a part oftransformer 13, during the initial conduction of oscillator 8 and intimed relation to the operation of the distributor 3 and the movement ofthe piston, not shown, to provide proper transfer of energy from thecapacitor 5 through the pulse transformer 4 to the gap 2.

More particularly in the illustrated embodiment of the invention, theoscillator circuit includes the transistor 11, shown as a PNP type,connected in a common emitter configuration; having an emitter 16, as aninput-output element, connected to the positive side of the battery 1and a collector 17, as an output element, connected to the one side ofthe primary winding 12. The opposite side of the transformer primarywinding 12 is connected to the negative side of the battery 1 through acommon ground connection 18. The transistor 11 includes a base 19 as theinput element which is connected to derive its power from the battery 1as follows. The base 19 is connected to the negative terminal of thebattery 1 through a dropping resistor 20 and a transistor 21 to groundwhich controls the turning on or conduction through the transistor 11.

The transistor 21 is shown as an NPN type having the collector connectedthrough resistor 20 to the base 19 and the emitter 23 connected to theground. terminal 18. An input base 24 of the transistor 21 is connectedto derive power from the collector 17 of transistor 11 after initiationof the triggering of the blocking oscillator 8. The connection to thecollector 17 is through a resistor 25, a resistor 26 and a sil concontrolled rectifier 27 to provide a selectively completed or triggeredvoltage dividing network. Thus, the feedback winding commonly used inblocking oscillators is eliminated. A feedback winding could be used;for example, other considerations necessitated the grounding ofcollector 17 of transistor 11.

The silicon controlled rectifier 27 includes an anode 28 connected tothe adjacent series resistor 26 and the cathode 29 connected to the base24 of transistor 21. A gate 30 of the silicon controlled rectifier 27controls conduction through the rectifier from the anode 28 to thecathode 29. The gate 30 is connected to the positive side of the battery1 through a direct current blocking capacitor 31 and the resistor 32.Switch 10 is connected between the negative side of battery 1 and thejunction of capacitor 31 and resistor 32. Thus, whenever switch 10 isopen, a circuit is momentarily completed from the positive side of thebattery through the resistor 32, capacitor 31, gate 30 and cathode 29 tothe base 24 of transistor 21 and then through the emitter 23 to thenegative side of the battery 1 and ground 18. Consequently, the siliconcontrolled rectifier 27 and transistor 21 will be biased to conduct andpermit current to flow and provide an input bias on the transistor whichin turn provides an inputsignal on the base 19 of transistor 11.Regenerative action to the base 24 of the transistor 21 causes it toconduct at a greater rate. The current will thus increase through thetransistors 11 and 21 and the series connected transformer primary 12with the energy being stored in the core 15. The square loop core unit 9is connected to cut off conduction.

When the switch 10 again closes, capacitor 31 discharges throughresistor 33.

The illustrated pulse forming circuit including switch 10 has been shownfor purposes of clearly illustrating the functioning of the oscillatorand may be replaced with any other appropriate timing means adapted togenerate a short duration pulse.

The core unit 9 may be of any known or suitable construction and isdiagrammatically shown including a winding 34 wound on a square loopcore 35. Thus, the inductance of winding 34 is relatively high until theknee of the core characteristic is reached and then rapidly changes to arelatively very small value. Winding 34 is connected between thejunction of resistors 25 and 26 and the emitter 23 of transistor 21 andthus directly across the circuit of the silicon controlled rectifier 27and the input circuit of the transistor 21. When transistor 11 begins toconduct, a part of the current is diverted through the winding 34 ofsquare loop core unit 9 which provides a relatively high impedance tothe current flow until it reaches saturation. When it changes to thesaturated condition, the reactance reduces substantially and essentiallyto zero and provides a direct bypass or shunt around the siliconcontrolled rectifier 27 and the input circuit of the transistor 21. Thesilicon controlled rectifier 27 and the transistor 21 stop conductingand the bias on the base 19 of the transistor 11 is removed. This opensthe circuit from the battery 1 to stop the input current flow. Thevoltage dividing resistors 25 and 26 are provided to insure reset of theunit 9 and to prevent excessive current in the circuit when unit 9 issaturated.

The core unit 9 thus acts as a switch sensitive to the volt-timeintegral applied to it. In the broadest aspect of the present invention,other switch means including semi-conductors connected to be turned onby either the volt-time integral applied or by the current throughwinding 12 of transformer 13, which is proportional to the volt-timeintegral, can be employed to regulate the energy in each cycle or singlepulse generated by the oscillator.

When the core unit 9 terminates conduction, the magnetic field in thecore 15 of the transformer 13 collapses and induces a voltage ofopposite polarity in the secondary winding 14 to cause a current flowthrough the Capacitor charging circuit which includes a blocking diode36, a protective diode 37 and a resistor 38 connected to the positiveside of the capacitor 5. The opposite side of the capacitor 5 isconnected to the opposite side of the transformer secondary 14. Thiswill permit charging of the capacitor to the selected value determinedby the cutoff of the oscillator 8 through the action of the square loopcore 9.

The capacitor 5 subsequently discharges through transformer 4 bytriggering of the silicon controlled rectifier 6.

Transformer 4 includes a primary 39 connected in series with the siliconcontrolled rectifier 6 directly across the capacitor 5. The illustratedtransformer 4 includes a secondary 40 connected across the spark gap 2in series with the distributor 3.

The silicon controlled rectifier 6 generally corresponds to therectifier 27 and includes a gate 41 connected to the trigger winding 7which is wound as a small secondary on the oscillator transformer 13.Winding 7 is wound with respect to the primary 12 to provide a triggerpulse during the starting cycle of the oscillator 8. Consequently, whenthe switch is opened to initiate operation of the oscillator 8, thetransformer winding 7 produces a firing pulse which causes rectifier 6to conduct and discharge the previous charge on the capacitor 5 throughthe pulse transformer 4 for firing of the spark gap 2.

Generally, in accordance with the teaching of applicants previouslyidentified copending application, a Zener diode is connected in parallelwith the silicon controlled rectifier as a protective device.

Additionally, in the illustrated embodiment of the invention, a simpletachometer circuit is connected in the circuit with the square loop coreunit 9 to provide an inexpensive speed readout device. The tachometercircuit includes a tachometer meter 43 connected in series with a diode44 and a resistor 45 between the junction of resistors 25 and 26 andthus the common connection to the square loop core unit 9. The oppositeside of the tachometer meter 43 is connected to ground as shown at 46.The volt-time integral across the square loop core unit 9 is essentiallythe same for all battery voltages. The oscillator circuit generallyproduces a volt-time integral which is independent of battery voltageand consequently the tachometer circuit may also be connected directlyacross the primary 12. The tachometer meter 43 indicates the averagecurrent and consequently gives an output signal directly proportional tothe speed at which the engine is turning over.

The operation of the illustrated embodiment of the invention may bebriefly summarized as follows.

The switch 10 is coupled to the distributor 3 to be driven in accordancewith the movement of the pistons of the internal-combustion engine inaccordance with any suitable or known system. The battery 1 provides asource of energy to the oscillator 8 which is transferred to thecapacitor 5 to charge it to a selected level whenever the switch 10 isopened to initiate conduction through a gate circuit of siliconcontrolled rectifier 27 and the input or base loop of transistor 21. Thetransistor 11 then conducts and provides a charging current until thesquare loop core unit 9 is saturated at which time it rapidly turns theoscillator off, terminating the charging of the transformer 13 andtransferring a charging pulse to the capacitor 5.

The next time the switch 10 is opened the charging cycle is againinitiated. The winding 7 fires the silicon controlled rectifier 6 andcompletes the discharge circuit for the capacitor 5 through the pulsetransformer 4. The capacitor 5 is therefore rapidly discharged throughthe pulse transformer to fire the proper spark gap 2 or the like duringthe charging of the transform er 13. The capacitor 5 cannot dischargeback to the transformer 13 as a result of the blocking diode 36.

The present invention provides a unique blocking oscillator employing acontrolled rectifier connected in the input circuit of the transistor orsimilar electronic switch means to initiate conduction. The controlledrectifier may be connected directly in circuit with the main oscillatortransistor 11 with the gate-circuit in series with the input elements ofthe transistor. Further, the preferred circuit employing the twotransistors provides a unique circuit for driving the oscillator withpower derived directly from the battery or other input power source.

The present invention thus provides an improved blocking oscillatorwhich provides a highly efficient means for controlling the charging ofthe capacitor 5 to a preselected level and maintains essentiallypredetermined constant operation independently of the level of thevoltage source over a wide variation in the voltage level thereof aswell as the operating speed of the engine over the ranges selected anddetermined by the particular value of the several components in thesystem. This energy level is primarily dependent upon thecharacteristics of the core unit 9 and transformer 13 and to a slightextent the resistors 25 and 26 and is essentially independent of theexact value of the switching element parameters of the oscillator suchas gain of the transistor and the exact value of the capacitor 5.

For purposes of the present invention, a blocking oscillator includes aninductive energy storage means connected to an energy source through aswitch means having at least one input means connected to derive powerin a feedback loop from the output and the storage means is connected inan output circuit to deliver the stored energy upon the decrease ofcurrent into the inductive energy storage means.

Various modes of carrying out the invention are contemplated as beingwithin the scope of the following claims particularly pointing out anddistinctly claiming the subject matter which is regarded as theinvention.

I claim:

1. An ignition system for an internal-combustion engine,

energy source means for the ignition system,

a blocking oscillator having an electronic switch means in series withan inductive energy storage means, said switch means having inputelements to initiate conduction and generation of a charging pulsesignal to said energy storage means and a square loop magnetic core unitconnected in the output circuit of the switch means to conduct onlyafter the switch means has initiated conduction to said energy storagemeans and operable to stop conduction through the switch means togenerate a single pulse of electrical energy and thereby provide apreselected energy per pulse stored in the inductive means essentiallyindependent of changes in engine speed and potential of said sourcemeans,

means connected to said input elements to initiate said cycleindependently of said square loop magnetic core unit, and

output circuit means to transfer the energy from the inductive means forfiring of the engine.

2. In an ignition system for internal-combustion engines and the likehaving igniting means in a combustion chamber to be fired from a sourceof current, comprising a capacitor,

a blocking oscillator means having an output means connected across thecapacitor and having an electronic switch for connecting the outputmeans to the source and including a magnetic control unit connected tothe output of the electronic switch and connected to effectively opensaid switch means in response to saturation of the magnetic controlunit,

an input signal means separate from said magnetic control unit andconnected to the switch means for effectively closing the switch meansand initiating a charging cycle independently of said magnetic controlunit, and

an output circuit connected to the capacitor and having output meansadapted to be connected to the igniting means for firing thereof andincluding circuit completing control means.

3. In a capacitor discharge ignition system for an internal-combustionengine,

a blocking oscillator having an inductive storage means,

a controlled rectifier connected to initiate a cycle of the blockingoscillator for generating a single pulse of current,

means to trigger the rectifier in accordance with the ignitionrequirement of the engine,

a switch means separate from said rectifier and connected in an outputcircuit of the oscillator in parallel with said rectifier and energizedby said pulse of current and responsive to a selected volttime integralto turn off the oscillator and terminate said single pulse of current,

a capacitor connected to the inductive storage means and charged inresponse to termination of the pulse, and

firing means to discharge the capacitor in timed relation to engineoperation.

4. In anignition system f or internal-combustion engines and the likehaving igniting means in a combustion chamber to be fired from a sourceof direct current, comprising a capacitor,

a blocking oscillator having an output means connected across thecapacitor and having a first transistor connecting the output means to asource and a second transistor connected in the input circuit of thefirst transistor, said oscillator including a gate controlled rectifierconnecting the output of the first transistor to the input of the secondtransistor,

a switch means responsive to the volt-time integral impressed thereonand connected in parallel with the gate controlled rectifier andeffective to turn off the gate controlled rectifier,

an output circuit connected to the capacitor and having output meansadapted to be connected to the igniting means for firing thereof andincluding control switch means, and a firing circuit connected tocontrol the switching means and actuate it to cause firing of theignition means. 5. The ignition system of claim 4 wherein said switchmeans is a magnetic unit having a winding connected in parallel with thecontrolled rectifier and the input of the second transistor, saidmagnetic unit turning off said control rectifier and said transistorupon saturation of the magnetic unit.

6. In an ignition system for internal-combustion engines and the likehaving igniting means in a combustion chamber to be fired from a sourceof direct current, comprising a capacitor,

a blocking oscillator including an oscillator output transformer and afirst transistor connected in a series circuit with a power connectionmeans and having a control transistor connected in series with an inputelement of the first transistor to the power connection means, saidoscillator having a con trolled rectifier connected in a series circuitwith an output element of the first transistor and an input element ofthe second transistor, said series circuit including a pair of voltagedividing element connected between the rectifier and the output element,

means operable in timed relation to the engine and connected to triggerthe controlled rectifier to initiate a charging cycle,

a square loop core unit having a winding connected at one end to thejunction of the voltage dividing elements and at the opposite end to anoutput element of the second transistor and turning off the oscillatorin response to a selected current through said winding,

circuit means connecting said capacitor to said oscillator outputtransformer to charge the capacitor when the oscillator turns off, and

means for connecting the capacitor to the igniting means and to theblocking oscillator and selectively operated in response to initiationof the charging cycle to discharge said capacitor.

7. A capacitor discharge ignition system for an internal-combustionengine having a firing means and a battery, the improvement in theconnection of the battery to the firing means comprising a blockingoscillator having an inductive storage means and an energy sourceconnection means,

a main transistor having an input element, an output element and acommon input-output element, the output element and the commoninput-output element being connected in a series circuit loop with thestorage means and the energy source connection means,

a control transistor having an input element, an output element and acommon input-output element, the output element and the commoninput-output element of the control transistor being connected,

in a series control loop with the input element and the commoninput-output element of the main transistor and the energy sourceconnection means,

9 10 means including a controlled rectifier for initiating a controlledrectifier and turning off the oscillator in cycle of the blockingoscillator and connecting the response to the volt-time integral of theoscillator input element of the control transistor to the outoutp i, andput element of the main transistor to derive a con- 3 eapaeltorConnected to the storege means and trol feedback signal from the maintransistor for 5 adapteqto be connected 9 the firlng means to besustaining that cycle of the blocking oscillator, sequentlany chargedand dischargedmeans paralleled with the control transistor and theUNITED STATES PATENT oTTTcE QERTIFICATE 0F QQRRECHQN.

Patent No. 3 687 123 Dated Auqust 29 1972 Inventoflx) FLOYD M. MINKS Itis certified that error appears in the above-identified patent and thatsaid Letters Patent are hereby corrected as shown below:

Title Page After Paragraph [21] insert vnew paragraph [73] AssigneeBrunswick Corporation, Chicago, Illinois Signed and sealed this 3rd dayof April 1973.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Commissionerof Patents ORM PO-1050(10-69) USCOMM-DC 60376-1 69 3 U45. GOVERNMENTPRIN ING OFFICE: 1969 0-366-334,

1. An ignition system for an internal-combustion engine, energy sourcemeans for the ignition system, a blocking oscillator having anelectronic switch means in series with an inductive energy storagemeans, said switch means having input elements to initiate conductionand generation of a charging pulse signal to said energy storage meansand a square loop magnetic core unit connected in the output circuit ofthe switch means to conduct only after the switch means has initiatedconduction to said energy storage means and operable to stop conductionthrough the switch means to generate a single pulse of electrical energyand thereby provide a preselected energy per pulse stored in theinductive means essentially independent of changes in engine speed andpotential of said source means, means connected to said input elementsto initiate said cycle independently of said square loop magnetic coreunit, and output circuit means to transfer the energy from the inductivemeans for firing of the engine.
 2. In an ignition system forinternal-combustion engines and the like having igniting means in acombustion chamber to be fired from a source of current, comprising acapacitor, a blocking oscillator means having an output means connectedacross the capacitor and having an electronic switch for connecting theoutput means to the source and including a magnetic control unitconnected to the output of the electronic switch and connected toeffectively open said switch means in response to saturation of themagnetic control unit, an input signal means separate from said magneticcontrol unit and connected to the switch means for effectively closingthe switch means and initiating a charging cycle independently of saidmagnetic control unit, and an output circuit connected to the capacitorand having output means adapted to be connected to the igniting meansfor firing thereof and including circuit completing control means.
 3. Ina capacitor discharge ignition system for an internal-combustion engine,a blocking oscillator having an inductive storage means, a controlledrectifier connected to initiate a cycle of the blocking oscillator forgenerating a single pulse of current, means to trigger the rectifier inaccordance with the ignition requirement of the engine, a switch meansseparate from said rectifier and connected in an output circuit of theoscillator in parallel with said rectifier and energized by said pulseof current and responsive to a Selected volt-time integral to turn offthe oscillator and terminate said single pulse of current, a capacitorconnected to the inductive storage means and charged in response totermination of the pulse, and firing means to discharge the capacitor intimed relation to engine operation.
 4. In an ignition system f orinternal-combustion engines and the like having igniting means in acombustion chamber to be fired from a source of direct current,comprising a capacitor, a blocking oscillator having an output meansconnected across the capacitor and having a first transistor connectingthe output means to a source and a second transistor connected in theinput circuit of the first transistor, said oscillator including a gatecontrolled rectifier connecting the output of the first transistor tothe input of the second transistor, a switch means responsive to thevolt-time integral impressed thereon and connected in parallel with thegate controlled rectifier and effective to turn off the gate controlledrectifier, an output circuit connected to the capacitor and havingoutput means adapted to be connected to the igniting means for firingthereof and including control switch means, and a firing circuitconnected to control the switching means and actuate it to cause firingof the ignition means.
 5. The ignition system of claim 4 wherein saidswitch means is a magnetic unit having a winding connected in parallelwith the controlled rectifier and the input of the second transistor,said magnetic unit turning off said control rectifier and saidtransistor upon saturation of the magnetic unit.
 6. In an ignitionsystem for internal-combustion engines and the like having ignitingmeans in a combustion chamber to be fired from a source of directcurrent, comprising a capacitor, a blocking oscillator including anoscillator output transformer and a first transistor connected in aseries circuit with a power connection means and having a controltransistor connected in series with an input element of the firsttransistor to the power connection means, said oscillator having acontrolled rectifier connected in a series circuit with an outputelement of the first transistor and an input element of the secondtransistor, said series circuit including a pair of voltage dividingelement connected between the rectifier and the output element, meansoperable in timed relation to the engine and connected to trigger thecontrolled rectifier to initiate a charging cycle, a square loop coreunit having a winding connected at one end to the junction of thevoltage dividing elements and at the opposite end to an output elementof the second transistor and turning off the oscillator in response to aselected current through said winding, circuit means connecting saidcapacitor to said oscillator output transformer to charge the capacitorwhen the oscillator turns off, and means for connecting the capacitor tothe igniting means and to the blocking oscillator and selectivelyoperated in response to initiation of the charging cycle to dischargesaid capacitor.
 7. A capacitor discharge ignition system for aninternal-combustion engine having a firing means and a battery, theimprovement in the connection of the battery to the firing meanscomprising a blocking oscillator having an inductive storage means andan energy source connection means, a main transistor having an inputelement, an output element and a common input-output element, the outputelement and the common input-output element being connected in a seriescircuit loop with the storage means and the energy source connectionmeans, a control transistor having an input element, an output elementand a common input-output element, the output element and the commoninput-output element of the control transistor being connected in aseries control loop with the input element and the common input-outputelement of the main transistor and the energy source coNnection means,means including a controlled rectifier for initiating a cycle of theblocking oscillator and connecting the input element of the controltransistor to the output element of the main transistor to derive acontrol feedback signal from the main transistor for sustaining thatcycle of the blocking oscillator, means paralleled with the controltransistor and the controlled rectifier and turning off the oscillatorin response to the volt-time integral of the oscillator output, and acapacitor connected to the storage means and adapted to be connected tothe firing means to be sequentially charged and discharged.